The present invention generally relates to an implantable device for treating tachyarrhythmias and more specifically relates to a device employing spinal cord stimulation to treat patients suffering from a variety of tachyarrhythmias.
Spinal cord stimulation has long been employed to treat patients suffering from chronic pain. For example, spinal cord stimulation for pain control is provided by the ITREL.RTM. implantable neurostimulators sold by Medtronic, Inc., Minneapolis Minn. It has also been proposed to combine spinal cord stimulation with cardiac monitoring and/or stimulation devices for a variety of purposes. For example, it has been proposed to combine spinal cord stimulation with implantable atrial defibrillators in order to reduce pain associated with delivery of defibrillation shocks. Such devices are disclosed in U.S. Pat. No. 5,817,131 issued to Elsberry et al. and U.S. Pat. No. 5,792,187 issued to Adams. Spinal cord stimulation in conjunction with an implanted pacemaker or heart monitor to treat angina, activated in response to detection of ischemia is proposed in U.S. Pat. No. 5,199,428 issued to Obel et al.
It has also been proposed to combine parasympathetic nerve stimulators with implantable tachyarrhythmia devices. Typically, such devices attempt to either slow intrinsic heart rhythms or decrease heart irritability to facilitate anti-tachyarrhythmia treatments such as antitachycardia pacing, cardioversion or defibrillation. Such devices are disclosed in U.S. Pat. No. 5,330,507 issued to Schwartz, U.S. Pat. No. 5,334,221 issued to Bardy, U.S. Pat. No. 5,356,425 issued to Bardy et al., U.S. Pat. No. 5,700,282 issued to Zybara and U.S. Pat. No. 5,203,326 issued to Collins. In these devices, nerve stimulation electrodes are placed generally adjacent either the vagal nerves themselves or the ganglionated plexi or "fat pads" located on the heart, associated with parasympathetic enervation of the heart.